Major airlines from around the world have begun re-routing flights to avoid areas around the Strait of Hormuz following Iran's shooting down of a US military surveillance drone.
The US Federal Aviation Administration warned of a "potential for miscalculation or misidentification" in the region after an Iranian surface-to-air missile brought down a US Navy RQ-4A Global Hawk, an unmanned aircraft with a wingspan larger than a Boeing 737 jetliner.
Etihad Airways has become the latest airline to announce it is suspending operations through Iranian airspace over the Strait of Hormuz and the Gulf of Oman.
In a statement on Saturday, the United Arab Emirates-based carrier said it will use alternative flight paths on a number of routes to and from Abu Dhabi "until further notice".
It added: "The safety of our passengers and staff is the highest priority for Etihad Airways, and we are continually engaging with regulatory authorities and conducting our own risk assessments to ensure that our standards are not compromised."
Australia's Qantas, British Airways, Dutch carrier KLM and Germany's Lufthansa said on Friday they were re-plotting routes to skirt the region.
Emirates, Singapore Airlines and Malaysia Airlines also later took similar steps.
The news came after it was revealed US President Donald Trump had been just hours away from ordering a retaliatory military strike against targets inside Iran.
"The threat of a civil aircraft shoot-down in southern Iran is real," warned OPSGROUP, a company that provides guidance to global airlines.
The FAA issued a similar warning in May to commercial airliners of the possibility of Iranian anti-aircraft gunners mistaking them for military aircraft, something dismissed by Tehran some 30 years after the US Navy shot down an Iranian passenger jet.
There are "heightened military activities and increased political tensions in the region, which present an inadvertent risk to U.S. civil aviation operations and potential for miscalculation or misidentification", the FAA said.
It said: "The risk to U.S. civil aviation is demonstrated by the Iranian surface-to-air missile shoot-down of a US unmanned aircraft system on 19 June 2019 while it was operating in the vicinity of civil air routes above the Gulf of Oman."
OPSGROUP said the Iranian weapons system that took out the drone was comparable to the Russian Buk system used in 2014 Malaysian Airlines attack in Ukraine.
"Any error in that system could cause it to find another target nearby - another reason not to be anywhere near this part of the Strait of Hormuz," OPSGROUP said.
Qantas said it would reroute its London flights to avoid the Strait of Hormuz and Gulf of Oman.
Dutch carrier KLM and British Airways said their flights would avoid the strait.
Lufthansa said it would avoid both the Strait of Hormuz and the Gulf of Oman, as well as nearby land.
However, it said it would continue its flights to Tehran.
Emirates said it was "rerouting all flights away from areas of possible conflict", while Singapore Airlines said that some of its flights will take "slightly longer routings" to avoid the area because of the ongoing tensions.
It said the safety was its top priority and that it "continuously reviews" the areas it overflies.
Malaysia Airlines said it has rerouted its flights to and from London, Jeddah and Medina because "safety is of utmost importance".
The Persian Gulf is home to some of the world's top long-haul carriers, who already have been battered by President Trump's travel bans targeting a group of predominantly Muslim countries, as well as an earlier ban on laptops in airplane cabins for Mideast carriers.